Collapsible helmet



FIG. 1 is a top, front perspective view of a design for a collapsiblehelmet;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a top, rear perspective view thereof;

FIG. 9 is a bottom, front perspective view thereof;

FIG. 10 is a bottom, rear perspective view thereof;

FIG. 11 is a top, front perspective view thereof, in a collapsedposition;

FIG. 12 is a front view of FIG. 11;

FIG. 13 is a rear view of FIG. 11;

FIG. 14 is a left side view of FIG. 11;

FIG. 15 is a right side view of FIG. 11;

FIG. 16 is a top view of FIG. 11;

FIG. 17 is a bottom view of FIG. 11;

FIG. 18 is a top, rear perspective view of FIG. 11;

FIG. 19 is a bottom, front perspective view of FIG. 11; and,

FIG. 20 is a bottom, rear perspective view of FIG. 11.

The details shown in broken lines are for illustrative purposes only andform no part of the claimed design.

CLAIM The ornamental design for a collapsible helmet, as shown anddescribed.